Abrasive materials handling draft inducer



1964 H. c. EDWARDS ABRASIVE MATERIALS HANDLING DRAFT INDUCER Filed April 18, 1962 mm c 50/1442 5? OR BY yofiw United States Patent 3,152,839 ABRASIVE MATERIALS HANDLING DRAFT INDUCER Howard C. Edwards,, 2443 Whipple Road NW.,

Canton, Ohio Filed Apr. 18, 1962, Ser. No. 188,474 3 Claims. (Cl. 302-45) The present invention relates to materials handling through pneumatic means; more specifically, the invention relates to the conveyance of comminuted materials, abrasives, sheet cuttings and the'like. This invention is closely related to United States Patent No. 2,722,372 entitled Draft Control Apparatus issued November 1, 1955, similar details of the patent being incorporated by reference herein.

This invention may generally be defined as a high pressure power draft unit interposed in pneumatic tubular conveyances or materials handling units, the present system being adapted specifically to create a: substantial negative pressure within the tubular conveyance and to augment the action of a high pressure blower. An effort is here made to create a substantially even flow of input air or related input gas, whereby to create an effective vacuum within the conveyance, said vacuum being caused by atmospheric pressure on the conveyance complex. In this system, the input air at high pressure is introduced at a plenum chamber substantially intermediate of the components comprising a venturi assembly. This assem- 'bly includes a compression member, an expansion memher in extension thereof, adjacent constricted ends of the respective members being spaced longitudinally to define a peripheral slot opening into the interior of the venturi assembly. In this invention, the inlet and exhaust ends respectively of the compression and expansion members are flared into sealed contact with the plenum chamber. Moreover, to effect the desired negative pressure within the tubular conveyance in the area precedent to attachment to the draft inducer, the discharge extremity of the plenum chamber is defined by adjacent parallel walls of the respective compression and expansion'members as will be more fully described hereinafter.

The objectives of invention include providing novel means for inducing a draft of high pressure into tubular pneumatic materials handling conveyance system whereby preservation of the components comprising the draft inducing unit and the tubular system may be maintained substantially free of wear and operative at maximum efiiciency. Further is the objective of creating a pneumatic materials handling aid whereby neither discrete materials handling nor the handling unit shall be affected by wear characteristics which may be caused by the movement of abrasives which are being conveyed. The draft inducer herein may be employed with or without chimney to exhaust noxious and abrasive fumes, ribbonlike, granular and related fluid materials which can be suspended and conveyed pneumatically.

These and other objectives of invention will appear from reference to the ensuing description and drawings in which:

FIGURE 1 is a vertical sectional view of invention; FIGURE 2 is an end view or the invention shown in FIGURE 1, taken from the intake end of the assembly.

bles, balls or other discrete granular materials such as may be conveyed by pneumatic means. a This venturi assembly includes an intake end and exhaust end and an artificial high pressure air input inlet adjacent a plenum chamber. The intake end 110 of the assembly defines the intake extremity of the plenum chamber having a closed cylindrical outer wall 112. This cylindrical wall continues to a point forward whereupon the respective walls forming the plenum chamber diverge at 114 to define a cone, the continuation of which comprises an expansion chamber 116 having an end 118 of greater ccosssectional area than the input end thereof. In completion of the venturi assembly, a compression or nozzle element 120 is sealed at its end to the intake end of the outer wall 112 of the plenum chamber, the respective outer and inner Walls of plenum chamber and compression member defining the plenum interior 132. It is to be noted that the compression element or nozzle 120 has its greater cross sectional area at the intake end thereof, the same diminishing in cross sectional dimension by virtue of the diverging cone-like wall 122, terminating to meet the frusto-conical end portion 124. This cone terminates in outlet 126. The respective opposed walls 124 of the compression members 120 and 114 of the plenum are parallel to each other, defining plenum outlet 134. This artificial exhaust channel 134 is designed to present maximum vacuum to the pneumatic conveyance by directing a pressurized cone of gas into the already compressed stream entering the intake at 110.

The inlet 110 of the nozzle is by connection to a pipe, not shown, open to the atmosphere. Input tube is adapted to mounting a high pressure blower of the turbine type. For instance, this invention is particularly adapted to accommodate turbo-wheel blowers which are designed to create as much as several thousand pounds pressure p.s.i. whereby a materials handling high pressure blower and draft inducer is introduced into a conduit between point of loading of conduit and unloading or exhaust therefrom, thus obtaining a constant negative pressure to the conveyor column. With respect to the disposition of connected walls 114 and 124, they are preferably disposed at an angle approximately 22 degrees from a centerline drawn through the axis of the assembly, creating hereby an extended apex to the induced high pressures, thereby augmenting the negative pressure at the intake end of the device, and thus creating higher efiiciency.

As shown, the interior of the respective venturi compression and expansion elements is lined with a resilient material such as sponge rubber to protect same from abrasive contact of conveyed materials. The opposed walls of 114 and 124, nevertheless are not lined, as they are not subjected to the likelihood of abrasion, being simply a channel for the artificially induced input gas.

A typical nozzle assembly made of 18 gauge metal currently being marketed consists of the following dimensrons:

(A) Expansion cone 116-7%" ID. at exhaust (B) Expansion cone 1l65%" ID. at input 134 (C) Rubber lining Miloverall thickness (D) Rubber lining 1411-5" I.D. expansion cone input (E) Expansion cone declination-2V2 length 20%" (F) Plenum 112 and 114 length 11%;

(G) Compression cone length 112 and 12410%" (H) Plenum exhaust 134-2'Vs" axial length and /2" width between walls (I) Plenum intake 120 I.D.7 /4" (J Plenum lining intake I.D.--6 /z" (K) Compression exhaust 126 I.D.5-' 7 (L) Compression lining exhaust I.D.-4

(M) Overall length of expansion and compression assembly--31 The advantages of the particular construction may be derived by like construction without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. In the pneumatic conveyance of comminutive and flexible material, draft inducing means including a venturi assembly comprising: a compression member constricted at its outlet end and a coaxial expansion member constricted at its inlet end, the adjacent constricted ends of said members being spaced longitudinally to define a peripheral slot, opening to the interior of said vcnturi assembly; a plenum means spaced radially outwardly from the compression member forming therewith a plenum chamber having a discharge extremity terminating in the peripheral slot defined between said exhaust and inlet ends respectively of the compression and expansion-members; said plenum discharge extremity comprising an inner wall in extension of the exhaust end of said compression member, said inner wall describing the sloping surface of a truncated cone, the largest portion of said inner wall corresponding to said compression member exhaust extremity, said plenum discharge extremity further comprising an outer wall in extension of the inlet end of said expansion member, said outer wall being parallel to said inner wall, and said outer wall describing the sloping surface of a truncated cone, a portion of said outer wall adjacent its smallest dimension corresponding to the inlet end of said expansion member; each of said compression and said expansion members being lined interiorly with a resilient material defining a substantially continuous line venturi; the parallel conical walls of said plenum discharge extremity extending over adjacent ends of said resilient material lining said members, and said walls being constructed of a non-resilient material; and draft inducing means operatively connected to the plenum chamber.

2. The draft inducing means of claim 1 wherein the passageway defined by the discharge extremity of the plenum chamber declines 22 degrees from a line passing through the center axis of the draft inducing means.

3. Draft inducing means according to claim 1 in which outlet and inlet ends of respective compression and expansion members are of equal diameter.

References Cited in the file of this patent UNITED STATES PATENTS 783,218 Murray Feb. 21, 1905 1,317,363 Gasche Sept. 30, 1919 2,107,084 'Pletcher Feb. 1, 1938 2,310,265 Sweeny Feb. 9, 194-3 

1. IN THE PNEUMATIC CONVEYANCE OF COMMINUTIVE AND FLEXIBLE MATERIAL, DRAFT INDUCING MEANS INCLUDING A VENTURI ASSEMBLY COMPRISING: A COMPRESSION MEMBER CONSTRICTED AT ITS OUTLET END AND A COXIAL EXPANSION MEMBER CONSTRICTED AT ITS INLET END, THE ADJACENT CONSTRICTED ENDS OF SAID MEMBERS BEING SPACED LONGITUDINALLY TO DEFINE A PERIPHERAL SLOT, OPENING TO THE INTERIOR OF SAID VENTURI ASSEMBLY; A PLENUM MEANS SPACED RADIALLY OUTWARDLY FROM THE COMPRESSION MEMBER FORMING THEREWITH A PLENUM CHAMBER HAVING A DISCHARGE EXTREMITY TERMINATING IN THE PERIPHERAL SLOT DEFINED BETWEEN SAID EXHAUST AND INLET ENDS RESPECTIVELY OF THE COMPRESSION AND EXPANSION MEMBERS; SAID PLENUM DISCHARGE EXTREMITY COMPRISING AN INNER WALL IN EXTENSION OF THE EXHAUST END OF SAID COMPRESSION MEMBER, SAID INNER WALL DISCRIBING THE SLOPING SURFACE OF A TRUNCATED CONE, THE LARGEST PORTION OF SAID INNER WALL CORRESPONDING TO SAID COMPRESSION MEMBER EXHAUST EXTREMITY, SAID PLENUM DISCHARGE EXTREMITY FURTHER COMPRISING AN OUTER WALL IN EXTENSION OF THE INLET END OF SAID EXPANSION MEMBER, SAID OUTER WALL BEING PARALLEL TO SAID INNER WALL, AND SAID OUTER WALL DESCRIBING THE SLOPING SURFACE OF A TRUNCATED CONE, A PORTION OF SAID OUTER WALL ADJACENT ITS SMALLEST DIMENSION CORRESPONDING TO THE INLET END OF SAID EXPANSION MEMBER; EACH OF SAID COMPRESSION AND SAID EXPANSION MEMBERS BEING LINED INTERIORLY WITH A RESILIENT MATERIAL DEFINING A SUBSTANTIALLY CONTINUOUS LINE VENTURI; THE PARALLEL CONICAL WALLS OF SAID PLENUM DISCHARGE EXTREMITY EXTENDING OVER ADJACENT ENDS OF SAID RESILIENT MATERIAL LINING SAID MEMBERS, AND SAID WALLS BEING CONSTRUCTED OF A NON-RESILIENT MATERIAL; AND DRAFT INDUCING MEANS OPERATIVELY CONNECTED TO THE PLENUM CHAMBER. 